“Esterquats” (EQ), the term generally being understood as meaning quaternized fatty acid triethanolamine ester salts, are widely suitable for softening both fibers and also hair and, in former years, have pushed conventional quaternary ammonium compounds, such as, for example, the known distearyldimethyl ammonium chloride, largely out of the market as a result of their better ecotoxicological compatibility.
Although the known esterquats have very favorable properties for industrial use and possess satisfactory biodegradability and favorable cosmetic compatibility with the skin, the preparations with esterquats that are known in the prior art have a disadvantage in being turbid. Though specific esterquats based on unsaturated fatty acids, with which optically clear formulations can be prepared, are available on the market, high concentrations of these esterquats are needed, as is the use of solvents, in order to be able to prepare clear fabric softener formulations that have the desired properties. This, in turn, is detrimental in terms of the costs of such formulations.
It is moreover desirable for such formulations to be viscous, without forming filaments, in order to enable simple handling and dosing. Finally, there are also considerable requirements regarding the stability of such formulations, because not only is a consistent usage-specific quality desired, but so too is the longest-lasting possible visually and olfactorily appealing structure of the product.